U.S. patent number 7,334,548 [Application Number 11/363,088] was granted by the patent office on 2008-02-26 for piston joint.
This patent grant is currently assigned to R. Sanderson Management, Inc.. Invention is credited to Albert E. Sanderson, Robert A. Sanderson.
United States Patent |
7,334,548 |
Sanderson , et al. |
February 26, 2008 |
Piston joint
Abstract
A joint for positioning between first and second elements
includes an outer member and an inner member. The first and second
elements are arranged for linear motion along a common axis. The
outer member is configured for movement relative to the first and
second elements along a first axis perpendicular to the common
axis, and the inner member is mounted within the outer member for
rotation relative to the outer member about a second axis
perpendicular to the first axis and the common axis and for
movement relative to the outer member along the second axis. The
outer member is restrained from movement along the second axis. The
outer member defines first and second parallel flat sides. Each
flat side defines a plane perpendicular to the common axis. The
outer and inner members each defining an opening for receiving a
drive arm.
Inventors: |
Sanderson; Robert A. (Denton,
TX), Sanderson; Albert E. (Carlisle, MA) |
Assignee: |
R. Sanderson Management, Inc.
(Denton, TX)
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Family
ID: |
25113956 |
Appl.
No.: |
11/363,088 |
Filed: |
February 28, 2006 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20060153633 A1 |
Jul 13, 2006 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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10925135 |
Aug 25, 2004 |
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09778629 |
Feb 7, 2001 |
7011469 |
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Current U.S.
Class: |
123/56.1; 123/63;
123/78R; 403/122; 403/128; 74/60 |
Current CPC
Class: |
F01B
3/0082 (20130101); F04B 27/0886 (20130101); Y10T
403/32861 (20150115); Y10T 403/32681 (20150115); Y10T
403/32631 (20150115); Y10T 74/18336 (20150115) |
Current International
Class: |
F02B
75/18 (20060101) |
Field of
Search: |
;403/52,65,67,150,157,122,128,131,161 ;92/71,140 ;417/534,539
;74/60 ;123/56.1,63,61R |
References Cited
[Referenced By]
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Primary Examiner: Kamen; Noah P.
Attorney, Agent or Firm: Fish & Richardson P.C.
Parent Case Text
This application is a continuation of application U.S. Ser. No.
10/925,135, filed Aug. 25, 2004 now abandoned, entitled PISTON
JOINT, which is a continuation of U.S. Ser. No. 09/778,629, filed
Feb. 7, 2001 now U.S. Pat. No. 7,011,469, entitled PISTON JOINT,
both applications are hereby incorporated by reference in their
entirety.
Claims
What is claimed is:
1. An apparatus comprising: at least one piston; a transition arm;
a joint coupling the piston to the transition arm, the joint
including: an outer member configured for movement relative to the
piston along a first axis, the outer member defining first and
second parallel flat sides, the outer member defining an opening
for receiving a portion of the transition arm, and an inner member
mounted within the outer member for rotation relative to the outer
member about a second axis and for movement relative to the outer
member along the second axis, the outer member being restrained
from movement along the second axis, the inner member defining an
opening for receiving the portion of the transition arm; and a
rotatable drum defining a cylinder, the cylinder housing the
piston.
2. The assembly of claim 1 further comprising: a face plate to
control a flow of fluid into and out of the cylinder.
3. The assembly of claim 1 wherein the at least one piston consists
of three pistons.
4. The assembly of claim 1 wherein the assembly comprises a
hydraulic pump.
5. The assembly of claim 1 wherein the assembly comprises a
compressor.
6. The assembly of claim 1 wherein the transition arm includes a
nose pin, the nose pin being moveable such that a radial position
of the nose pin relative to an axis of the assembly is adjustable
to change a stroke of the pistons.
7. The assembly of claim 1 further comprising: a bearing block
coupled to the transition arm; and a member defining an arced
channel that houses the bearing block, wherein the bearing block is
configured to slide within the arced channel to change an angle of
the transition arm relative to an axis of the assembly.
8. The assembly of claim 7 wherein the arced channel is configured
to allow the bearing block to slide to a position such that the
angle of the transition arm relative to the axis is substantially
zero.
9. The assembly of claim 1 further comprising: a universal joint
connecting the transition arm to a support.
10. The assembly of claim 9 wherein the universal joint connects
the transition arm to the support by two pins to permit pivoting
motion about two axes.
11. The assembly of claim 1 wherein the outer member comprises a
two-piece member, each piece of the two-piece member including a
first concave inner face.
12. The assembly of claim 11 wherein each piece of the two-piece
member includes an additional concave inner face arranged
perpendicular to the first concave inner face.
13. The assembly of claim 1 wherein the outer member comprises a
two-piece member, each piece of the two-piece member including a
flat outer face defining one of the first and second parallel flat
sides.
14. The assembly of claim 1 wherein the outer member comprises a
two-piece member, each piece of the two-piece member defining one
of the first and second parallel flat sides and including a curved
outer wall.
15. The assembly of claim 14 wherein the outer member comprises a
two-piece member, each piece of the two-piece member including two
curved outer walls.
16. The assembly of claim 1 wherein the outer member comprises a
two-piece member, each piece of the two-piece member having first
and second concave perpendicular cut-outs on an inner face, a flat
outer face defining one of the first and second parallel flat
sides, and two curved side walls.
17. An engine comprising: at least one piston; a transition arm; a
joint coupling the piston to the transition arm, the joint
including: an outer member configured for movement relative to the
piston along a first axis, the outer member defining first and
second parallel flat sides, the outer member defining an opening
for receiving a portion of the transition arm, and an inner member
mounted within the outer member for rotation relative to the outer
member about a second axis and for movement relative to the outer
member along the second axis, the outer member being restrained
from movement along the second axis, the inner member defining an
opening for receiving the drive arm; a universal joint connecting
the transition arm to a support; a cylinder housing pistons and
having a spark plug and inlet and exhaust valves; at least one cam
shaft; and a distributor for controlling the timing of the spark
plug and the cam shaft for the operation of the inlet and exhaust
valves.
18. The assembly of claim 17 wherein the transition arm includes a
nose pin, the assembly further comprising: a rotatable flywheel
coupled to the nose pin such that a radial position of the nose pin
relative to an axis of rotation of the rotatable member is
adjustable.
19. The assembly of claim 17 wherein the universal joint connects
the transition arm to the support by two pins to permit pivoting
motion about two axes.
20. The piston assembly of claim 19 wherein the at least one piston
comprises a plurality of pistons that include first and second
pistons having axes lying on a common plane, the piston assembly
further comprising a rotating member coupled to the transition arm
and having an axis of rotation that lies other than on the common
plane.
Description
BACKGROUND OF THE INVENTION
The invention relates to a piston joint.
Most piston driven engines have pistons that are attached to offset
portions of a crankshaft such that as the pistons are moved in a
reciprocal direction transverse to the axis of the crankshaft, the
crankshaft will rotate.
U.S. Pat. No. 5,535,709, defines an engine with a double ended
piston that is attached to a crankshaft with an off set portion. A
lever attached between the piston and the crankshaft is restrained
in a fulcrum regulator to provide the rotating motion to the
crankshaft.
U.S. Pat. No. 4,011,842, defines a four cylinder piston engine that
utilizes two double ended pistons connected to a T-shaped
connecting member that causes a crankshaft to rotate. The T-shaped
connecting member is attached at each of the T-cross arm to a
double ended piston. A centrally located point on the T-cross arm
is rotatably attached to a fixed point, and the bottom of the T is
rotatably attached to a crank pin which is connected to the
crankshaft by a crankthrow which includes a counter weight.
In each of the above examples, double ended pistons are used that
drive a crankshaft that has an axis transverse to the axis of the
pistons.
SUMMARY OF THE INVENTION
According to one aspect of the invention, a joint for positioning
between first and second elements includes an outer member and an
inner member. The first and second elements are arranged for linear
motion along a common axis. The outer member is configured for
movement relative to the first and second elements along a first
axis perpendicular to the common axis, and the inner member is
mounted within the outer member for rotation relative to the outer
member about a second axis perpendicular to the first axis and the
common axis and for movement relative to the outer member along the
second axis. The outer member is restrained from movement along the
second axis. The outer member defines first and second parallel
flat sides. Each flat side defines a plane perpendicular to the
common axis. The outer and inner members each defining an opening
for receiving a drive arm.
Embodiments of this aspect of the invention may include one or more
of the following features.
The inner member is cylindrical. The outer member is configured to
rotate about the common axis. The outer member is a two-piece
member. Each piece of the two-piece member includes a first concave
inner face, an additional concave inner face arranged perpendicular
to the first concave inner face, a flat outer face, and two curved
outer walls.
In an illustrated embodiment, the first and second elements are
each pistons. Alternatively, the first element is a piston and the
second element is a guided rod. The joint includes a connector for
mounting of the first and second elements thereto. The connector
defining a cavity, and the outer member and the inner member are
positioned within the cavity. The cavity is rectangular and has
four flat inner walls.
According to another aspect of the invention, a method of reducing
side load in a double ended member includes providing a joint
located between first and second elements, and transferring load
between the first and second elements and a drive arm mounted to
the joint through two opposed surfaces of an outer member of the
joint.
Advantages of the invention include a joint for coupling a piston
to a drive arm where transfer of side load and twisting motion
between the drive arm and piston is limited reducing friction and
wear of the assembly.
Other features and advantages of the invention will be apparent
from the following description and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 are side view of a simplified illustration of a four
cylinder engine of the present invention;
FIGS. 3, 4, 5 and 6 are a top views of the engine of FIG. 1 showing
the pistons and flywheel in four different positions;
FIG. 7 is a top view, partially in cross-section of an eight
cylinder engine of the present invention;
FIG. 8 is a side view in cross-section of the engine of FIG. 7;
FIG. 9 is a right end view of FIG. 7;
FIG. 10 is a side view of FIG. 7;
FIG. 11 is a left end view of FIG. 7;
FIG. 12 is a partial top view of the engine of FIG. 7 showing the
pistons, drive member and flywheel in a high compression
position;
FIG. 13 is a partial top view of the engine in FIG. 7 showing the
pistons, drive member and flywheel in a low compression
position;
FIG. 14 is a top view of a piston;
FIG. 15 is a side view of a piston showing the drive member in two
positions;
FIG. 16 shows the bearing interface of the drive member and the
piston;
FIG. 17 is an air driven engine/pump embodiment;
FIG. 18 illustrates the air valve in a first position;
FIGS. 18a, 18b and 18c are cross-sectional view of three
cross-sections of the air valve shown in FIG. 18;
FIG. 19 illustrates the air valve in a second position;
FIGS. 19a, 19b and 19c are cross-sectional view of three
cross-sections for the air valve shown in FIG. 19;
FIG. 20 shows an embodiment with slanted cylinders;
FIG. 21 shows an embodiment with single ended pistons;
FIG. 22 is a top view of a two cylinder, double ended piston
assembly;
FIG. 23 is a top view of one of the double ended pistons of the
assembly of FIG. 22;
FIG. 23a is a side view of the double ended piston of FIG. 23,
taken along lines 23A, 23A;
FIG. 24 is a top view of a transition arm and universal joint of
the piston assembly of FIG. 22;
FIG. 24a is a side view of the transition arm and universal joint
of FIG. 24, taken along lines 24a, 24a;
FIG. 25 is a perspective view of a drive arm connected to the
transition arm of the piston assembly of FIG. 22;
FIG. 25a is an end view of a rotatable member of the piston
assembly of FIG. 22, taken along lines 25a, 25a of FIG. 22, and
showing the connection of the drive arm to the rotatable
member;
FIG. 25b is a side view of the rotatable member, taken along lines
25b, 25b of FIG. 25a;
FIG. 26 is a cross-sectional, top view of the piston assembly of
FIG. 22;
FIG. 27 is an end view of the transition arm, taken along lines 27,
27 of FIG. 24;
FIG. 27a is a cross-sectional view of a drive pin of the piston
assembly of FIG. 22;
FIGS. 28-28b are top, rear, and side views, respectively, of the
piston assembly of FIG. 22;
FIG. 28c is a top view of an auxiliary shaft of the piston assembly
of FIG. 22;
FIG. 29 is a cross-sectional side view of a zero-stroke
coupling;
FIG. 29a is an exploded view of the zero-stroke coupling of FIG.
29;
FIG. 30 is a graph showing the FIG. 8 motion of a non-flat piston
assembly;
FIG. 31 shows a reinforced drive pin;
FIG. 32 is a top view of a four cylinder engine for directly
applying combustion pressures to pump pistons;
FIG. 32a is an end view of the four cylinder engine, taken along
lines 32a, 32a of FIG. 32;
FIG. 33 is a cross-sectional top view of an alternative embodiment
of a variable stroke assembly shown in a maximum stroke
position;
FIG. 34 is a cross-sectional top view of the embodiment of FIG. 33
shown in a minimum stroke position;
FIG. 35 is a partial, cross-sectional top view of an alternative
embodiment of a double-ended piston joint;
FIG. 35A is an end view and FIG. 35B is a side view of the
double-ended piston joint, taken along lines 35A, 35A and 35B, 35B,
respectively, of FIG. 35;
FIG. 36 is a partial, cross-sectional top view of the double-ended
piston joint of FIG. 35 shown in a rotated position;
FIG. 37 is a side view of an alternative embodiment of the joint of
FIG. 35;
FIG. 38 is a top view of an engine/compressor assembly;
FIG. 38A is an end view and FIG. 38B is a side view of the
engine/compressor assembly, taken along lines 38A, 38A and 38B,
38B, respectively, of FIG. 38;
FIG. 39 is a perspective view of a piston engine assembly including
counterbalancing;
FIG. 40 is a perspective view of the piston engine assembly of FIG.
39 in a second position;
FIG. 41 is a perspective view of an alternative embodiment of a
piston engine assembly including counterbalancing;
FIG. 42 is a perspective view of the piston engine assembly of FIG.
41 in a second position.
FIG. 43 is a perspective view of an additional alternative
embodiment of a piston engine assembly including
counterbalancing;
FIG. 44 is a perspective view of the piston engine assembly of FIG.
43 in a second position;
FIG. 45 is a perspective view of an additional alternative
embodiment of a piston engine assembly including
counterbalancing;
FIG. 46 is a perspective view of the piston engine assembly of FIG.
43 in a second position;
FIG. 47 is a side view showing the coupling of a transition arm to
a flywheel;
FIG. 48 is a side view of an alternative coupling of the transition
arm to the flywheel;
FIG. 49 is a side view of an additional alternative coupling of the
transition arm to the flywheel;
FIG. 50 is a cross-sectional side view of a hydraulic pump;
FIG. 51 is an end view of a face valve of the hydraulic pump of
FIG. 50;
FIG. 52 is a cross-sectional view of the hydraulic pump of FIG. 30,
taken along lines 52-52;
FIG. 53 is an end view of a face plate of the hydraulic pump of
FIG. 50;
FIG. 54 is a partially cut-away side view of a variable compression
piston assembly;
FIG. 55 is a cross-sectional side view of the piston assembly of
FIG. 54, taken along lines 55-55;
FIG. 56 is a side view of an alternative embodiment of a piston
joint;
FIGS. 56A and 56B are top and end views, respectively, of the
piston joint of FIG. 56;
FIG. 56C is an exploded perspective view of the piston joint of
FIG. 56;
FIG. 56D is an exploded view of inner and outer members of the
piston joint of FIG. 56; and
FIGS. 56E and 56F are side and inner face views, respectively, of
an outer member of the piston joint of FIG. 56.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a pictorial representation of a four piston engine 10 of
the present invention. Engine 10 has two cylinders 11 (FIG. 3) and
12. Each cylinder 11 and 12 house a double ended piston. Each
double ended piston is connected to transition arm 13 which is
connected to flywheel 15 by shaft 14. Transition arm 13 is
connected to support 19 by a universal joint mechanism, including
shaft 18, which allows transition arm 13 to move up an down and
shaft 17 which allows transition arm 13 to move side to side. FIG.
1 shows flywheel 15 in a position shaft 14 at the top of wheel
15.
FIG. 2 shows engine 10 with flywheel 15 rotated so that shaft 14 is
at the bottom of flywheel 15. Transition arm 13 has pivoted
downward on shaft 18.
FIGS. 3-6 show a top view of the pictorial representation, showing
the transition arm 13 in four positions and shaft moving flywheel
15 in 90.degree. increments. FIG. 3 shows flywheel 15 with shaft 14
in the position as illustrated in FIG. 3a. When piston 1 fires and
moves toward the middle of cylinder 11, transition arm 13 will
pivot on universal joint 16 rotating flywheel 15 to the position
shown in FIG. 2. Shaft 14 will be in the position shown in FIG. 4a.
When piston 4 is fired, transition arm 13 will move to the position
shown in FIG. 5. Flywheel 15 and shaft 14 will be in the position
shown in FIG. 5a. Next piston 2 will fire and transition arm 13
will be moved to the position shown in FIG. 6. Flywheel 15 and
shaft 14 will be in the position shown in FIG. 6a. When piston 3 is
fired, transition arm 13 and flywheel 15 will return to the
original position that shown in FIGS. 3 and 3a.
When the pistons fire, transition arm will be moved back and forth
with the movement of the pistons. Since transition arm 13 is
connected to universal joint 16 and to flywheel 15 through shaft
14, flywheel 15 rotates translating the linear motion of the
pistons to a rotational motion.
FIG. 7 shows (in partial cross-section) a top view of an embodiment
of a four double piston, eight cylinder engine 30 according to the
present invention. There are actually only four cylinders, but with
a double piston in each cylinder, the engine is equivalent to a
eight cylinder engine. Two cylinders 31 and 46 are shown. Cylinder
31 has double ended piston 32, 33 with piston rings 32a and 33a,
respectively. Pistons 32, 33 are connected to a transition arm 60
(FIG. 8) by piston arm 54a extending into opening 55a in piston 32,
33 and sleeve bearing 55. Similarly piston 47, 49, in cylinder 46
is connected by piston arm 54b to transition arm 60.
Each end of cylinder 31 has inlet and outlet valves controlled by a
rocker arms and a spark plug. Piston end 32 has rocker arms 35a and
35b and spark plug 44, and piston end 33 has rocker arms 34a and
34b, and spark plug 41. Each piston has associated with it a set of
valves, rocker arms and a spark plug. Timing for firing the spark
plugs and opening and closing the inlet and exhaust values is
controlled by a timing belt 51 which is connected to pulley 50a.
Pulley 50a is attached to a gear 64 by shaft 63 (FIG. 8) turned by
output shaft 53 powered by flywheel 69. Belt 50a also turns pulley
50b and gear 39 connected to distributor 38. Gear 39 also turns
gear 40. Gears 39 and 40 are attached to cam shaft 75 (FIG. 8)
which in turn activate push rods that are attached to the rocker
arms 34, 35 and other rocker arms not illustrated.
Exhaust manifolds 48 and 56 as shown attached to cylinders 46 and
31 respectively. Each exhaust manifold is attached to four exhaust
ports.
FIG. 8 is a side view of engine 30, with one side removed, and
taken through section 8-8 of FIG. 7. Transitions arm 60 is mounted
on support 70 by pin 72 which allows transition arm to move up and
down (as viewed in FIG. 8) and pin 71 which allows transition arm
60 to move from side to side. Since transition arm 60 can move up
and down while moving side to side, then shaft 61 can drive
flywheel 69 in a circular path. The four connecting piston arms
(piston arms 54b and 54d shown in FIG. 8) are driven by the four
double end pistons in an oscillator motion around pin 71. The end
of shaft 61 in flywheel 69 causes transition arm to move up and
down as the connection arms move back and forth. Flywheel 69 has
gear teeth 69a around one side which may be used for turning the
flywheel with a starter motor 100 (FIG. 11) to start the
engine.
The rotation of flywheel 69 and drive shaft 68 connected thereto,
turns gear 65 which in turn turns gears 64 and 66. Gear 64 is
attached to shaft 63 which turns pulley 50a. Pulley 50a is attached
to belt 51. Belt 51 turns pulley 50b and gears 39 and 40 (FIG. 7).
Cam shaft 75 has cams 88-91 on one end and cams 84-87 on the other
end. Cams 88 and 90 actuate push rods 76 and 77, respectively. Cams
89 and 91 actuate push rods 93 and 94, respectively. Cams 84 and 86
actuate push rods 95 and 96, respectively, and cams 85 and 87
actuate push rods 78 and 79, respectively. Push rods 77, 76, 93,
94, 95, 96 and 78, 79 are for opening and closing the intake and
exhaust valves of the cylinders above the pistons. The left side of
the engine, which has been cutaway, contains an identical, but
opposite valve drive mechanism.
Gear 66 turned by gear 65 on drive shaft 68 turns pump 67, which
may be, for example, a water pump used in the engine cooling system
(not illustrated), or an oil pump.
FIG. 9 is a rear view of engine 30 showing the relative positions
of the cylinders and double ended pistons. Piston 32, 33 is shown
in dashed lines with valves 35c and 35d located under lifter arms
35a and 35b, respectively. Belt 51 and pulley 50b are shown under
distributor 38. Transition arm 60 and two, 54c and 54d, of the four
piston arms 54a, 54b, 54c and 54d are shown in the pistons 32-33,
32a-33a, 47-49 and 47a-49a.
FIG. 10 is a side view of engine 30 showing the exhaust manifold
56, intake manifold 56a and carburetor 56c. Pulleys 50a and 50b
with timing belt 51 are also shown.
FIG. 11 is a front end view of engine 30 showing the relative
positions of the cylinders and double ended pistons 32-33, 32a-33a,
47-49 and 47a-49a with the four piston arms 54a, 54b, 54 and 54d
positioned in the pistons. Pump 67 is shown below shaft 53, and
pulley 50a and timing belt 51 are shown at the top of engine 30.
Starter 100 is shown with gear 101 engaging the gear teeth 69a on
flywheel 69.
A feature of the invention is that the compression ratio for the
engine can be changed while the engine is running. The end of arm
61 mounted in flywheel 69 travels in a circle at the point where
arm 61 enters flywheel 69. Referring to FIG. 13, the end of arm 61
is in a sleeve bearing ball bushing assembly 81. The stroke of the
pistons is controlled by arm 61. Arm 61 forms an angle, for example
about 15.degree., with shaft 53. By moving flywheel 69 on shaft 53
to the right or left, as viewed in FIG. 13, the angle of arm 61 can
be changed, changing the stroke of the pistons, changing the
compression ratio. The position of flywheel 69 is changed by
turning nut 104 on threads 105. Nut 104 is keyed to shaft 53 by
thrust bearing 106a held in place by ring 106b. In the position
shown in FIG. 12, flywheel 69 has been moved to the right,
extending the stroke of the pistons.
FIG. 12 shows flywheel moved to the right increasing the stroke of
the pistons, providing a higher compression ratio. Nut 105 has been
screwed to the right, moving shaft 53 and flywheel 69 to the right.
Arm 61 extends further into bushing assembly 80 and out the back of
flywheel 69.
FIG. 13 shows flywheel moved to the left reducing the stroke of the
pistons, providing a lower compression ratio. Nut 105 has been
screwed to the left, moving shaft 53 and flywheel 69 to the left.
Arm 61 extends less into bushing assembly 80.
The piston arms on the transition arm are inserted into sleeve
bearings in a bushing in piston. FIG. 14 shows a double piston 110
having piston rings 111 on one end of the double piston and piston
rings 112 on the other end of the double piston. A slot 113 is in
the side of the piston. The location the sleeve bearing is shown at
114.
FIG. 15 shows a piston arm 116 extending into piston 110 through
slot 116 into sleeve bearing 117 in bushing 115. Piston arm 116 is
shown in a second position at 116a. The two pistons arms 116 and
116a show the movement limits of piston arm 116 during operation of
the engine.
FIG. 16 shows piston arm 116 in sleeve bearing 117. Sleeve bearing
117 is in pivot pin 115. Piston arm 116 can freely rotate in sleeve
bearing 117 and the assembly of piston arm 116. Sleeve bearing 117
and pivot pin 115 and sleeve bearings 118a and 118b rotate in
piston 110, and piston arm 116 can be moved axially with the axis
of sleeve bearing 117 to allow for the linear motion of double
ended piston 110, and the motion of a transition arm to which
piston arm 116 is attached.
FIG. 17 shows how the four cylinder engine 10 in FIG. 1 may be
configured as an air motor using a four way rotary valve 123 on the
output shaft 122. Each of cylinders 1, 2, 3 and 4 are connected by
hoses 131, 132, 133, and 144, respectively, to rotary valve 123.
Air inlet port 124 is used to supply air to run engine 120. Air is
sequentially supplied to each of the pistons 1a, 2a, 3a and 4a, to
move the pistons back and forth in the cylinders. Air is exhausted
from the cylinders out exhaust port 136.
Transition arm 126, attached to the pistons by connecting pins 127
and 128 are moved as described with references to FIGS. 1-6 to turn
flywheel 129 and output shaft 22.
FIG. 18 is a cross-sectional view of rotary valve 123 in the
position when pressurized air or gas is being applied to cylinder 1
through inlet port 124, annular channel 125, channel 126, channel
130, and air hose 131. Rotary valve 123 is made up of a plurality
of channels in housing 123 and output shaft 122. The pressurized
air entering cylinder 1 causes piston 1a, 3a to move to the right
(as viewed in FIG. 18). Exhaust air is forced out of cylinder 3
through line 133 into chamber 134, through passageway 135 and out
exhaust outlet 136.
FIGS. 18a, 18b and 18c are cross-sectional view of valve 23 showing
the air passages of the valves at three positions along valve 23
when positioned as shown in FIG. 18.
FIG. 19 shows rotary valve 123 rotated 180.degree. when pressurized
air is applied to cylinder 3, reversing the direction of piston 1a,
3a. Pressurized air is applied to inlet port 124, through annular
chamber 125, passage way 126, chamber 134 and air line 133 to
cylinder 3. This in turn causes air in cylinder 1 to be exhausted
through line 131, chamber 130, line 135, annular chamber 137 and
out exhaust port 136. Shaft 122 will have rotated 360.degree.
turning counter clockwise when piston 1a, 3a complete it stroke to
the left.
Only piston 1a,3a have been illustrated to show the operation of
the air engine and valve 123 relative to the piston motion. The
operation of piston 2a,4a is identical in function except that its
360.degree. cycle starts at 90.degree. shaft rotation and reverses
at 270.degree. and completes its cycle back at 90.degree.. A power
stroke occurs at every 90.degree. of rotation.
FIGS. 19a, 19b and 19c are cross-sectional views of valve 123
showing the air passages of the valves at three positions along
valve 123 when positioned as shown in FIG. 19.
The principle of operation which operates the air engine of FIG. 17
can be reversed, and engine 120 of FIG. 17 can be used as an air or
gas compressor or pump. By rotating engine 10 clockwise by applying
rotary power to shaft 122, exhaust port 136 will draw in air into
the cylinders and port 124 will supply air which may be used to
drive, for example air tool, or be stored in an air tank.
In the above embodiments, the cylinders have been illustrated as
being parallel to each other. However, the cylinders need not be
parallel. FIG. 20 shows an embodiment similar to the embodiment of
FIGS. 1-6, with cylinders 150 and 151 not parallel to each other.
Universal joint 160 permits the piston arms 152 and 153 to be at an
angle other than 90.degree. to the drive arm 154. Even with the
cylinders not parallel to each other the engines are functionally
the same.
Still another modification may be made to the engine 10 of FIGS.
1-6. This embodiment, pictorially shown in FIG. 21, may have single
ended pistons. Piston 1a and 2a are connected to universal joint
170 by drive arms 171 and 172, and to flywheel 173 by drive arm
174. The basic difference is the number of strokes of pistons 1a
and 2a to rotate flywheel 173 360.degree..
Referring to FIG. 22, a two cylinder piston assembly 300 includes
cylinders 302, 304, each housing a variable stroke, double ended
piston 306, 308, respectively. Piston assembly 300 provides the
same number of power strokes per revolution as a conventional four
cylinder engine. Each double ended piston 306, 308 is connected to
a transition arm 310 by a drive pin 312, 314, respectively.
Transition arm 310 is mounted to a support 316 by, e.g., a
universal joint 318 (U-joint), constant velocity joint, or
spherical bearing. A drive arm 320 extending from transition arm
310 is connected to a rotatable member, e.g., flywheel 322.
Transition arm 310 transmits linear motion of pistons 306, 308 to
rotary motion of flywheel 322. The axis, A, of flywheel 322 is
parallel to the axes, B and C, of pistons 306, 308 (though axis, A,
could be off-axis as shown in FIG. 20) to form an axial or barrel
type engine, pump, or compressor. U-joint 318 is centered on axis,
A. As shown in FIG. 28a, pistons 306, 308 are 180? apart with axes
A, B and C lying along a common plane, D, to form a flat piston
assembly.
Referring to FIGS. 22 and 23, cylinders 302, 304 each include left
and right cylinder halves 301a, 301b mounted to the assembly case
structure 303. Double ended pistons 306, 308 each include two
pistons 330 and 332, 330a and 332a, respectively, joined by a
central joint 334, 334a, respectively. The pistons are shown having
equal length, though other lengths are contemplated. For example,
joint 334 can be off-center such that piston 330 is longer than
piston 332. As the pistons are fired in sequence 330a, 332, 330,
332a, from the position shown in FIG. 22, flywheel 322 is rotated
in a clockwise direction, as viewed in the direction of arrow 333.
Piston assembly 300 is a four stroke cycle engine, i.e., each
piston fires once in two revolutions of flywheel 322.
As the pistons move back and forth, drive pins 312, 314 must be
free to rotate about their common axis, E, (arrow 305), slide along
axis, E, (arrow 307) as the radial distance to the center line, B,
of the piston changes with the angle of swing, .alpha., of
transition arm 310 (approximately .+-.15.degree. swing), and pivot
about centers, F, (arrow 309). Joint 334 is constructed to provide
this freedom of motion.
Joint 334 defines a slot 340 (FIG. 23a) for receiving drive pin
312, and a hole 336 perpendicular to slot 340 housing a sleeve
bearing 338. A cylinder 341 is positioned within sleeve bearing 338
for rotation within the sleeve bearing. Sleeve bearing 338 defines
a side slot 342 shaped like slot 340 and aligned with slot 340.
Cylinder 341 defines a through hole 344. Drive pin 312 is received
within slot 342 and hole 344. An additional sleeve bearing 346 is
located in through hole 344 of cylinder 341. The combination of
slots 340 and 342 and sleeve bearing 338 permit drive pin 312 to
move along arrow 309. Sleeve bearing 346 permits drive pin 312 to
rotate about its axis, E, and slide along its axis, E.
If the two cylinders of the piston assembly are configured other
than 180.degree. apart, or more than two cylinders are employed,
movement of cylinder 341 in sleeve bearing 338 along the direction
of arrow 350 allows for the additional freedom of motion required
to prevent binding of the pistons as they undergo a FIG. 8 motion,
discussed below. Slot 340 must also be sized to provide enough
clearance to allow the FIG. 8 motion of the pin.
Referring to FIGS. 35-35B, an alternative embodiment of a central
joint 934 for joining pistons 330 and 332 is configured to produce
zero side load on pistons 330 and 332. Joint 934 permits the four
degrees of freedom necessary to prevent binding of drive pin 312 as
the pistons move back and forth, i.e., rotation about axis, E,
(arrow 905), pivoting about center, F, (arrow 909), and sliding
movement along orthogonal axes, M (up and down in the plane of the
paper in FIG. 35) and N (in and out of the plane of the paper in
FIG. 35), while the load transmitted between joint 934 and pistons
330, 332 only produces a force vector which is parallel to piston
axis, B (which is orthogonal to axes M and N).
Sliding movement along axis, M, accommodates the change in the
radial distance of transition arm 310 to the center line, B, of the
piston with the angle of swing, .alpha., of transition arm 310.
Sliding movement along axis, N, allows for the additional freedom
of motion required to prevent binding of the pistons as they
undergo the figure eight motion, discussed below. Joint 934 defines
two opposed flat faces 937, 937a which slide in the directions of
axes M and N relative to pistons 330, 332. Faces 937, 937a define
parallel planes which remain perpendicular to piston axis, B,
during the back and forth movement of the pistons.
Joint 934 includes an outer slider member 935 which defines faces
937, 937a for receiving the driving force from pistons 330, 332.
Slider member 935 defines a slot 940 in a third face 945 of the
slider for receiving drive pin 312, and a slot 940a in a fourth
face 945a. Slider member 935 has an inner wall 936 defining a hole
939 perpendicular to slot 940 and housing a slider sleeve bearing
938. A cross shaft 941 is positioned within sleeve bearing 938 for
rotation within the sleeve bearing in the direction of arrow 909.
Sleeve bearing 938 defines a side slot 942 shaped like slot 940 and
aligned with slot 940. Cross shaft 941 defines a through hole 944.
Drive pin 312 is received within slot 942 and hole 944. A sleeve
bearing 946 is located in through hole 944 of cross shaft 941.
The combination of slots 940 and 942 and sleeve bearing 938 permit
drive pin 312 to move in the direction of arrow 909. Positioned
within slot 940a is a cap screw 947 and washer 949 which attach to
drive pin 312 retaining drive pin 312 against a step 951 defined by
cross shaft 941 while permitting drive pin 312 to rotate about its
axis, E, and preventing drive pin 312 from sliding along axis, E.
As discussed above, the two addition freedoms of motion are
provided by sliding of slider faces 937, 937a relative to pistons
330, 332 along axis, M and N. A plate 960 is placed between each of
face 937 and piston 330 and face 937a and piston 332. Each plate
960 is formed of a low friction bearing material with a bearing
surface 962 in contact with faces 937, 937a, respectively. Faces
937, 937a are polished.
As shown in FIG. 36, the load, P.sub.L, applied to joint 934 by
piston 330 in the direction of piston axis, B, is resolved into two
perpendicular loads acting on pin 312: axial load, A.sub.L, along
the axis, E, of drive pin 312, and normal load, N.sub.L,
perpendicular to drive pin axis, E. The axial load is applied to
thrust bearings 950, 952, and the normal load is applied to sleeve
bearing 946. The net direction of the forces transmitted between
pistons 330, 332 and joint 934 remains along piston axis, B,
preventing side loads being applied to pistons 330, 332. This is
advantageous because side loads on pistons 330, 332 can cause the
pistons to contact the cylinder wall creating frictional losses
proportional to the side load values.
Pistons 330, 332 are mounted to joint 934 by a center piece
connector 970. Center piece 970 includes threaded ends 972, 974 for
receiving threaded ends 330a and 332a of the pistons, respectively.
Center piece 970 defines a cavity 975 for receiving joint 934. A
gap 976 is provided between joint 934 and center piece 970 to
permit motion along axis, N.
For an engine capable of producing, e.g., about 100 horsepower,
joint 934 has a width, W, of, e.g., about 3 5/16 inches, a length,
L.sub.1, of, e.g., 3 5/16 inches, and a height, H, of, e.g., about
31/2 inches. The joint and piston ends together have an overall
length, L.sub.2, of, e.g., about 9 5/16 inches, and a diameter,
D.sub.1, of, e.g., about 4 inches. Plates 960 have a diameter,
D.sub.2, of, e.g., about 31/4 inch, and a thickness, T, of, e.g.,
about 1/8 inch. Plates 960 are press fit into the pistons. Plates
960 are preferably bronze, and slider 935 is preferably steel or
aluminum with a steel surface defining faces 937, 937a.
Joint 934 need not be used to join two pistons. One of pistons 330,
332 can be replaced by a rod guided in a bushing.
Where figure eight motion is not required or is allowed by motion
of drive pin 312 within cross shaft 941, joint 934 need not slide
in the direction of axis, N. Referring to FIG. 37, slider member
935a and plates 960a have curved surfaces permitting slider member
935a to slide in the direction of axis, M, (in and out of the paper
in FIG. 37) while preventing slider member 935a to move along axis,
N.
Referring to FIGS. 56-56F, a piston joint 2300 includes a housing
2302, an outer member 2304 having first and second parts 2304a,
2304b, and an inner cylindrical member 2306. Housing 2302 includes
extensions 2308 and a rectangular shaped enclosure 2310. In FIG.
56, one extension 2308 includes a mount 2308a to which a piston or
plunger (not shown) is coupled, with the opposite extension 2308
acting as guide rods. In FIG. 56A, both extensions 2308 are shown
with mounts 2308a to which a double-ended piston or plunger is
coupled. Enclosure 2310 defines a rectangular shaped opening 2312
(FIG. 56C) in which outer member 2304 and inner member 2306 are
positioned. Opening 2312 is defined by four flat inner walls 2312a,
2312b, 2312c, 2312d of enclosure 2310.
Referring particularly to FIGS. 56C and 56D, parts 2304a, 2304b
each have a flat outer, end wall 2314, defining a plane
perpendicular to an axis, X, defined by mounts 2308, two parallel
flat sides 2316, and two curved side walls 2318. Parts 2304a, 2304b
also have an inner end wall 2320 with a concave cut-out 2322. When
assembled, concave cut-outs 2322 define an opening 2322a (FIG. 56A)
between parts 2304a, 2304b for receiving inner member 2306. Inner
end wall 2320 also defines two, sloped concave cut-outs 2324
perpendicular to cut-outs 2322 and positioned between sloped edges
2326, for purposes described below. Parts 2304a, 2304b are sized
relative to opening 2312 to be free to slide along an axis, Y,
perpendicular to axis, X, (arrow A), but are restricted by walls
2312a, 2312b from sliding along an axis, Z, perpendicular to axes,
X and Y (arrow B).
Inner member 2306 defines a through hole 2330 for receiving a
transition arm drive arm 2332. Inner member 2306 is shorter in the
Z direction than opening 2312 in housing 2302 such that inner
member 2306 can slide within opening 2312 along axis, Z, (arrow B).
Located between drive arm 2332 and inner member 2306 is a sleeve
bearing 2334 which facilitates rotation of drive arm 2332 relative
to inner member 2306 about axis, Y, arrow (D) (FIG. 56D). Drive arm
2332 is coupled to inner member 2306 by a threaded stud 2338,
washer 2340, nut 2342, and thrust washers 2344 and 2346. Stud 2338
is received within a threaded hole 2339 in arm 2332. Inner member
2306 is countersunk at 2306a to receive washer 2346. Thrust washer
2346 includes a tab 2348 received in a notch (not shown) in inner
member 2306 to prevent rotation of thrust washer 2346 relative to
inner member 2306. Thrust washer 2344 is formed, e.g., of steel,
with a polished surface facing thrust washer 2346. Thrust washer
2346 has, e.g., a Teflon surface facing thrust washer 2344 to
provide low friction between washers 2344 and 2346, and a copper
backing. An additional thrust washer 2350, formed, e.g., of bronze,
is positioned between inner member 2306 and the transition arm.
Piston joint 2300 includes an oil path 2336 (FIG. 56A) for flow of
lubrication.
Arm 2332, inner member 2306, outer member parts 2304a and 2304b,
and bearing 2334 include through holes 2352 that define oil path
2336. Alternatively, bearing 2334 can be formed from two rings with
a gap between the rings for flow of oil.
In operation, outer member 2304 and inner member 2306 slide
together relative to housing 2302 along axis, Y, (arrow A), inner
member 2306 slides relative to outer member 2304 along axis, Z,
(arrow B), inner member 2306 rotates relative to outer member 2304
about axis, Z, (arrow C), and drive arm 2332 rotates relative to
inner member 2306 about axis, Y, (arrow D). Load is transferred
between outer member 2304 and housing 2302 along vectors parallel
to axis, X, by flat sides 2314 of outer member 2304 and flat walls
2312c and 2312d of housing 2302, thus limiting the transfer of any
side loads to the pistons.
Depending on the layout and number of cylinders, motion of drive
arm 2332 can also cause inner member 2306 to rotate about axis, X.
For example, in a three cylinder pump, with the top cylinder in
line with the U-joint fixed axis, and the second and third
cylinders spaced 120 degrees, the drive arms for the second and
third cylinders undergo a twisting motion which is part of the FIG.
8 motion describe above. This motion causes rotation of inner
member 2306 of the respective joints about axis, X. This twisting
motion is taking place at twice the rpm frequency. Unless further
steps are taken, housing 2302 and the pistons would also twist
about axis, X, at twice the rpm frequency.
Inner member 2306 of the joint for the top piston does not undergo
twist about axis, X, because its drive pin is confined to motion in
a straight line by the U-joint.
In the piston joint of FIG. 35, outer member 935 is free to rotate
about axis, B (corresponding to axis, X of FIG. 56), thus the
twisting motion of the drive arm is not transferred to the pistons.
In the piston joint of FIG. 56, since outer member 2304 is
restrained from moving in the direction of axis, Z, curved side
walls 2318 of parts 2304a, 2304b are provided for accommodating the
motion about axis, X. Referring particularly to FIGS. 56E and 56F,
walls 2318 are radiused over an angle, .alpha., of about
.+-.2.degree., that blends into a tangent plane at the same
2.degree. angle on both sides of a center line, L. This provides
another degree of freedom enabling parts 2304a, 2304b to rotate
within opening 2312 about axis, X, in response to motion of inner
member 2306 about axis, X, without transferring this motion to
housing 2302. Since inner member 2306 of the joint for the top
piston does not undergo this motion, side walls 2318 of outer
member 2304 of this joint preferably have flat sides that allow no
angular movement, which controls the angle of the pistons in the
top cylinder.
To maintain control of the angular position of the remaining
pistons, it is preferable that curved side walls 2318 have radiused
sections which extend the minimum amount necessary to limit
transfer of the motion about axis, X, to housing 2302. Outer member
2304 acts to nudge the piston to a set angle on the first
revolution of the engine or pump. If the piston deviates from that
angle, the piston is forced back by the action of outer member 2304
at the end of travel of the piston. The contact between curved
walls 2318 and side walls 2312a, 2312b of housing 2302 is a line
contact, but this contact has no work to do in normal use, and the
contact line moves on both parts, distributing any wear taking
place.
Referring to FIGS. 24 and 24a, U-joint 318 defines a central pivot
352 (drive pin axis, E, passes through center 352), and includes a
vertical pin 354 and a horizontal pin 356. Transition arm 310 is
capable of pivoting about pin 354 along arrow 358, and about pin
356 along arrow 360.
Referring to FIGS. 25, 25a and 25b, as an alternative to a
spherical bearing, to couple transition arm 310 to flywheel 322,
drive arm 320 is received within a cylindrical pivot pin 370
mounted to the flywheel offset radially from the center 372 of the
flywheel by an amount, e.g., 2.125 inches, required to produce the
desired swing angle, .alpha. (FIG. 22), in the transition arm.
Pivot pin 370 has a through hole 374 for receiving drive arm 320.
There is a sleeve bearing 376 in hole 374 to provide a bearing
surface for drive arm 320. Pivot pin 370 has cylindrical extensions
378, 380 positioned within sleeve bearings 382, 384, respectively.
As the flywheel is moved axially along drive arm 320 to vary the
swing angle, .alpha., and thus the compression ratio of the
assembly, as described further below, pivot pin 370 rotates within
sleeve bearings 382, 384 to remain aligned with drive arm 320.
Torsional forces are transmitted through thrust bearings 388, 390,
with one or the other of the thrust bearings carrying the load
depending on the direction of the rotation of the flywheel along
arrow 386.
Referring to FIG. 26, to vary the compression and displacement of
piston assembly 300, the axial position of flywheel 322 along axis,
A, is varied by rotating a shaft 400. A sprocket 410 is mounted to
shaft 400 to rotate with shaft 400. A second sprocket 412 is
connected to sprocket 410 by a roller chain 413. Sprocket 412 is
mounted to a threaded rotating barrel 414. Threads 416 of barrel
414 contact threads 418 of a stationary outer barrel 420.
Rotation of shaft 400, arrow 401, and thus sprockets 410 and 412,
causes rotation of barrel 414. Because outer barrel 420 is fixed,
the rotation of barrel 414 causes barrel 414 to move linearly along
axis, A, arrow 403. Barrel 414 is positioned between a collar 422
and a gear 424, both fixed to a main drive shaft 408. Drive shaft
408 is in turn fixed to flywheel 322. Thus, movement of barrel 414
along axis, A, is translated to linear movement of flywheel 322
along axis, A. This results in flywheel 322 sliding along axis, H,
of drive arm 320 of transition arm 310, changing angle, .beta., and
thus the stroke of the pistons. Thrust bearings 430 are located at
both ends of barrel 414, and a sleeve bearing 432 is located
between barrel 414 and shaft 408.
To maintain the alignment of sprockets 410 and 412, shaft 400 is
threaded at region 402 and is received within a threaded hole 404
of a cross bar 406 of assembly case structure 303. The ratio of the
number of teeth of sprocket 412 to sprocket 410 is, e.g., 4:1.
Therefore, shaft 400 must turn four revolutions for a single
revolution of barrel 414. To maintain alignment, threaded region
402 must have four times the threads per inch of barrel threads
416, e.g., threaded region 402 has thirty-two threads per inch, and
barrel threads 416 have eight threads per inch.
As the flywheel moves to the right, as viewed in FIG. 26, the
stroke of the pistons, and thus the compression ratio, is
increased. Moving the flywheel to the left decreases the stroke and
the compression ratio. A further benefit of the change in stroke is
a change in the displacement of each piston and therefore the
displacement of the engine. The horsepower of an internal
combustion engine closely relates to the displacement of the
engine. For example, in the two cylinder, flat engine, the
displacement increases by about 20% when the compression ratio is
raised from 6:1 to 12:1. This produces approximately 20% more
horsepower due alone to the increase in displacement The increase
in compression ratio also increases the horsepower at the rate of
about 5% per point or approximately 25% in horsepower. If the
horsepower were maintained constant and the compression ratio
increased from 6:1 to 12:1, there would be a reduction in fuel
consumption of approximately 25%.
The flywheel has sufficient strength to withstand the large
centrifugal forces seen when assembly 300 is functioning as an
engine. The flywheel position, and thus the compression ratio of
the piston assembly, can be varied while the piston assembly is
running.
Piston assembly 300 includes a pressure lubrication system. The
pressure is provided by an engine driven positive displacement pump
(not shown) having a pressure relief valve to prevent
overpressures. Bearings 430 and 432 of drive shaft 408 and the
interface of drive arm 320 with flywheel 322 are lubricated via
ports 433 (FIG. 26).
Referring to FIG. 27, to lubricate U-joint 318, piston pin joints
306, 308, and the cylinder walls, oil under pressure from the oil
pump is ported through the fixed U-joint bracket to the top and
bottom ends of the vertical pivot pin 354. Oil ports 450, 452 lead
from the vertical pin to openings 454, 456, respectively, in the
transition arm. As shown in FIG. 27A, pins 312, 314 each define a
through bore 458. Each through bore 458 is in fluid communication
with a respective one of openings 454, 456. As shown in FIG. 23,
holes 460, 462 in each pin connect through slots 461 and ports 463
through sleeve bearing 338 to a chamber 465 in each piston. Several
oil lines 464 feed out from these chambers and are connected to the
skirt 466 of each piston to provide lubrication to the cylinders
walls and the piston rings 467. Also leading from chamber 465 is an
orifice to squirt oil directly onto the inside of the top of each
piston for cooling.
Referring to FIGS. 28-28c, in which assembly 300 is shown
configured for use as an aircraft engine 300a, the engine ignition
includes two magnetos 600 to fire the piston spark plugs (not
shown). Magnetos 600 and a starter 602 are driven by drive gears
604 and 606 (FIG. 28c), respectively, located on a lower shaft 608
mounted parallel and below the main drive shaft 408. Shaft 608
extends the full length of the engine and is driven by gear 424
(FIG. 26) of drive shaft 408 and is geared with a one to one ratio
to drive shaft 408. The gearing for the magnetos reduces their
speed to half the speed of shaft 608. Starter 602 is geared to
provide sufficient torque to start the engine.
Camshafts 610 operate piston push rods 612 through lifters 613.
Camshafts 610 are geared down 2 to 1 through bevel gears 614, 616
also driven from shaft 608. Center 617 of gears 614, 616 is
preferably aligned with U-joint center 352 such that the camshafts
are centered in the piston cylinders, though other configurations
are contemplated. A single carburetor 620 is located under the
center of the engine with four induction pipes 622 routed to each
of the four cylinder intake valves (not shown). The cylinder
exhaust valves (not shown) exhaust into two manifolds 624.
Engine 300a has a length, L, e.g., of about forty inches, a width,
W, e.g., of about twenty-one inches, and a height, H, e.g., of
about twenty inches, (excluding support 303).
Referring to FIGS. 29 and 29a, a variable compression compressor or
pump having zero stroke capability is illustrated. Here, flywheel
322 is replaced by a rotating assembly 500. Assembly 500 includes a
hollow shaft 502 and a pivot arm 504 pivotally connected by a pin
506 to a hub 508 of shaft 502. Hub 508 defines a hole 510 and pivot
arm 504 defines a hole 512 for receiving pin 506. A control rod 514
is located within shaft 502. Control rod 514 includes a link 516
pivotally connected to the remainder of rod 514 by a pin 518. Rod
514 defines a hole 511 and link 516 defines a hole 513 for
receiving pin 518. Control rod 514 is supported for movement along
its axis, Z, by two sleeve bearings 520. Link 516 and pivot arm 514
are connected by a pin 522. Link 516 defines a hole 523 and pivot
arm 514 defines a hole 524 for receiving pin 522.
Cylindrical pivot pin 370 of FIG. 25 which receives drive arm 320
is positioned within pivot arm 504. Pivot arm 504 defines holes 526
for receiving cylindrical extensions 378, 380. Shaft 502 is
supported for rotation by bearings 530, e.g., ball, sleeve, or
roller bearings. A drive, e.g., pulley 532 or gears, mounted to
shaft 502 drives the compressor or pump.
In operation, to set the desired stroke of the pistons, control rod
514 is moved along its axis, M, in the direction of arrow 515,
causing pivot arm 504 to pivot about pin 506, along arrow 517, such
that pivot pin 370 axis, N, is moved out of alignment with axis, M,
(as shown in dashed lines) as pivot arm 504 slides along the axis,
H, (FIG. 26) of the transition arm drive arm 320. When zero stroke
of the pistons is desired, axes M and N are aligned such that
rotation of shaft 514 does not cause movement of the pistons. This
configuration works for both double ended and single sided
pistons.
The ability to vary the piston stroke permits shaft 514 to be run
at a single speed by drive 532 while the output of the pump or
compressor can be continually varied as needed. When no output is
needed, pivot arm 504 simply spins around drive arm 320 of
transition arm 310 with zero swing of the drive arm. When output is
needed, shaft 514 is already running at full speed so that when
pivot arm 504 is pulled off-axis by control rod 514, an immediate
stroke is produced with no lag coming up to speed. There are
therefore much lower stress loads on the drive system as there are
no start/stop actions. The ability to quickly reduce the stroke to
zero provides protection from damage especially in liquid pumping
when a downstream blockage occurs.
An alternative method of varying the compression and displacement
of the pistons is shown in FIG. 33. The mechanism provides for
varying of the position of a counterweight attached to the flywheel
to maintain system balance as the stroke of the pistons is
varied.
A flywheel 722 is pivotally mounted to an extension 706 of a main
drive shaft 708 by a pin 712. By pivoting flywheel 722 in the
direction of arrow, Z, flywheel 722 slides along axis, H, of a
drive arm 720 of transition arm 710, changing angle, .beta. (FIG.
26), and thus the stroke of the pistons. Pivoting flywheel 722 also
causes a counterweight 714 to move closer to or further from axis,
A, thus maintaining near rotational balance.
To pivot flywheel 722, an axially and rotationally movable pressure
plate 820 is provided. Pressure plate 820 is in contact with a
roller 822 rotationally mounted to counterweight 714 through a pin
824 and bearing 826. From the position shown in FIG. 33, a servo
motor or hand knob 830 turns a screw 832 which advances to move
pressure plate 820 in the direction of arrow, Y. This motion of
pressure plate 820 causes flywheel 722 to pivot in the direction of
arrow, Z, as shown in the FIG. 34, to decrease the stroke of the
pistons. Moving pressure plate 820 by 0.75'' decreases the
compression ratio from about 12:1 to about 6:1.
Pressure plate 820 is supported by three or more screws 832. Each
screw has a gear head 840 which interfaces with a gear 842 on
pressure plate 820 such that rotation of screw 832 causes rotation
of pressure plate 820 and thus rotation of the remaining screws to
insure that the pressure plate is adequately supported. To ensure
contact between roller 822 and pressure plate 820, a piston 850 is
provided which biases flywheel 722 in the direction opposite to
arrow, Z.
Referring to FIG. 30, if two cylinders not spaced 180.degree. apart
(as viewed from the end) or more than two cylinders are employed in
piston assembly 300, the ends of pins 312, 314 coupled to joints
306, 308 will undergo a FIG. 8 motion. FIG. 30 shows the FIG. 8
motion of a piston assembly having four double ended pistons. Two
of the pistons are arranged flat as shown in FIG. 22 (and do not
undergo the FIG. 8 motion), and the other two pistons are arranged
equally spaced between the flat pistons (and are thus positioned to
undergo the largest FIG. 8 deviation possible). The amount that the
pins connected to the second set of pistons deviate from a straight
line (y axis of FIG. 30) is determined by the swing angle (mast
angle) of the drive arm and the distance the pin is from the
central pivot point 352 (x axis of FIG. 30).
In a four cylinder version where the pins through the piston pivot
assembly of each of the four double ended pistons are set at
45.degree. from the axis of the central pivot, the figure eight
motion is equal at each piston pin. Movement in the piston pivot
bushing is provided where the figure eight motion occurs to prevent
binding.
When piston assembly 300 is configured for use, e.g., as a diesel
engines, extra support can be provided at the attachment of pins
312, 314 to transition arm 310 to account for the higher
compression of diesel engines as compared to spark ignition
engines. Referring to FIG. 31, support 550 is bolted to transition
arm 310 with bolts 551 and includes an opening 552 for receiving
end 554 of the pin.
Engines according to the invention can be used to directly apply
combustion pressures to pump pistons. Referring to FIGS. 32 and
32a, a four cylinder, two stroke cycle engine 600 (each of the four
pistons 602 fires once in one revolution) applies combustion
pressure to each of four pump pistons 604. Each pump piston 604 is
attached to the output side 606 of a corresponding piston cylinder
608. Pump pistons 604 extend into a pump head 610.
A transition arm 620 is connected to each cylinder 608 and to a
flywheel 622, as described above. An auxiliary output shaft 624 is
connected to flywheel 622 to rotate with the flywheel, also as
described above.
The engine is a two stroke cycle engine because every stroke of a
piston 602 (as piston 602 travels to the right as viewed in FIG.
32) must be a power stroke. The number of engine cylinders is
selected as required by the pump. The pump can be a fluid or gas
pump. In use as a multi-stage air compressor, each pump piston 606
can be a different diameter. No bearing loads are generated by the
pumping function (for single acting pump compressor cylinders), and
therefore, no friction is introduced other than that generated by
the pump pistons themselves.
Referring to FIGS. 38-38B, an engine 1010 having vibration
canceling characteristics and being particularly suited for use in
gas compression includes two assemblies 1012, 1014 mounted
back-to-back and 180.degree. out of phase. Engine 1010 includes a
central engine section 1016 and outer compressor sections 1018,
1020. Engine section 1016 includes, e.g., six double acting
cylinders 1022, each housing a pair of piston 1024, 1026. A power
stroke occurs when a center section 1028 of cylinder 1022 is fired,
moving pistons 1024, 1026 away from each other. The opposed
movement of the pistons results in vibration canceling.
Outer compression section 1018 includes two compressor cylinders
1030 and outer compression section 1020 includes two compressor
cylinders 1032, though there could be up to six compressor
cylinders in each compression section. Compression cylinders 1030
each house a compression piston 1034 mounted to one of pistons 1024
by a rod 1036, and compression cylinders 1032 each house a
compression piston 1038 mounted to one of pistons 1026 by a rod
1040. Compression cylinders 1030, 1032 are mounted to
opposite-piston pairs such that the forces cancel minimizing
vibration forces which would otherwise be transmitted into mounting
1041.
Pistons 1024 are coupled by a transition arm 1042, and pistons 1026
are coupled by a transition arm 1044, as described above.
Transition arm 1042 includes a drive arm 1046 extending into a
flywheel 1048, and transition arm 1044 includes a drive arm 1050
extending into a flywheel 1052, as described above. Flywheel 1048
is joined to flywheel 1052 by a coupling arm 1054 to rotate in
synchronization therewith. Flywheels 1048, 1052 are mounted on
bearings 1056. Flywheel 1048 includes a bevel gear 1058 which
drives a shaft 1060 for the engine starter, oil pump and
distributor for ignition, not shown.
Engine 1010 is, e.g., a two stroke natural gas engine having ports
(not shown) in central section 1028 of cylinders 1022 and a
turbocharger (not shown) which provides intake air under pressure
for purging cylinders 1022. Alternatively, engine 1010 is gasoline
or diesel powered.
The stroke of pistons 1024, 1026 can be varied by moving both
flywheels 1048, 1052 such that the stroke of the engine pistons and
the compressor pistons are adjusted equally reducing or increasing
the engine power as the pumping power requirement reduces or
increases, respectively.
The vibration canceling characteristics of the back-to-back
relationship of assemblies 1012, 1014 can be advantageously
employed in a compressor only system and an engine only system.
Counterweights can be employed to limit vibration of the piston
assembly. Referring to FIG. 39, an engine 1100 includes
counterweights 1114 and 1116. Counterweight 1114 is mounted to
rotate with a rotatable member 1108, e.g., a flywheel, connected to
drive arm 320 extending from transition arm 310. Counterweight 1116
is mounted to lower shaft 608 to rotate with shaft 608.
Movement of the double ended pistons 306, 308 is translated by
transition arm 310 into rotary motion of member 1108 and
counterweight 1114. The rotation of member 1108 causes main drive
shaft 408 to rotate. Mounted to shaft 408 is a first gear 1110
which rotates with shaft 408. Mounted to lower shaft 608 is a
second gear 1112 driven by gear 1110 to rotate at the same speed as
gear 1110 and in the opposite direction to the direction of
rotation of gear 1110. The rotation of gear 1112 causes rotation of
shaft 608 and thus rotation of counterweight 1116.
As viewed from the left in FIG. 39, counterweight 1114 rotates
clockwise (arrow 1118) and counterweight 1116 rotates
counterclockwise (arrow 1120). Counterweights 1114 and 1116 are
mounted 180 degrees out of phase such that when counterweight 1114
is above shaft 408, counterweight 1116 is below shaft 608. A
quarter turn results in both counterweights 1114, 1116 being to the
right of their respective shafts (see FIG. 40). After another
quarter turn, counterweight 1114 is below shaft 408 and
counterweight 1116 is above shaft 608. Another quarter turn and
both counterweights are to the left of their respective shafts.
Referring to FIG. 40, movement of pistons 306, 308 along the Y
axis, in the plane of the XY axes, creates a moment about the Z
axis, M.sub.zy. When counterweights 1114, 1116 are positioned as
shown in FIG. 40, the centrifugal forces due to their rotation
creates forces, F.sub.x1 and F.sub.x2, respectively, parallel to
the X axis. These forces act together to create a moment about the
Z axis, M.sub.zx. The weight of counterweights 1114, 1116 is
selected such that M.sub.zx substantially cancels M.sub.zy.
When pistons 306, 308 are centered on the X axis (FIG. 39) there
are no forces acting on pistons 306, 308, and thus no moment about
the Z axis. In this position, counterweights 1114, 1116 are in
opposite positions as shown in FIG. 39 and the moments created
about the X axis by the centrifugal forces on the counterweights
cancel. The same is true after 180 degrees of rotation of shafts
408 and 608, when the pistons are again centered on the X axis and
the counterweight 1114 is below shaft 408 and counterweight 1116 is
above shaft 608.
Between the quarter positions, the moments about the X axis due to
rotation of counterweights 1114 and 1116 cancel, and the moments
about the Z axis due to rotation of counterweights 1114 and 1116
add.
Counterweight 1114 also accounts for moments produced by drive arm
320.
In other piston configurations, for example where pistons 306, 308
do not lie on a common plane or where there are more than two
pistons, counterweight 1116 is not necessary because at no time is
there no moment about the Z axis requiring the moment created by
counterweight 1114 to be cancelled.
One moment not accounted for in the counterbalancing technique of
FIGS. 39 and 40 a moment about axis Y, M.sub.yx, produced by
rotation of counterweight 1116. Another embodiment of a
counterbalancing technique which accounts for all moments is shown
in FIG. 41. Here, a counterweight 1114a mounted to rotating member
1108 is sized to only balance transition arm 310. Counterweights
1130, 1132 are provided to counterbalance the inertial forces of
double-ended pistons 306, 308.
Counterweight 1130 is mounted to gear 1110 to rotate clockwise with
gear 1110. Counterweight 1132 is driven through a pulley system
1134 to rotate counterclockwise. Pulley system 1134 includes a
pulley 1136 mounted to rotate with shaft 608, and a chain or timing
belt 1138. Counterweight 1132 is mounted to shaft 408 by a pulley
1140 and bearing 1142. Counterclockwise rotation of pulley 1136
causes counterclockwise rotation of chain or belt 1138 and
counterclockwise rotation of counterweight 1132.
Referring to FIG. 42, as discussed above, movement of pistons 306,
308 along the Y axis, in the plane of the XY axes, creates a moment
about the Z axis, M.sub.zy. When counterweights 1130, 1132 are
positioned as shown in FIG. 42, the centrifugal forces due to their
rotation creates forces, F.sub.x3 and F.sub.x4, respectively, in
the same direction along the X axis. These forces act together to
create a moment about the Z axis, M.sub.zx. The weight of
counterweights 1130, 1132 is selected such that M.sub.zx
substantially cancels M.sub.zy.
When pistons 306, 308 are centered on the X axis (FIG. 41) there
are no forces acting on pistons 306, 308, and thus no moment about
the Z axis. In this position, counterweights 1130, 1132 are in
opposite positions as shown in FIG. 41 and the moments created
about the X axis by the centrifugal forces on the counterweights
cancel. The same is true after 180 degrees of rotation of shafts
408 and 608, when the pistons are again centered on the X axis and
the counterweight 1130 is below shaft 408 and counterweight 1132 is
above shaft 408.
Between the quarter positions, the moments about the X axis due to
rotation of counterweights 1130 and 1132 cancel, and the moments
about the Z axis due to rotation of counterweights 1130 and 1132
add. Since counterweights 1130 and 1132 both rotate about the Y
axis, there is no moment M.sub.yx created about axis Y.
Counterweights 1130, 1132 are positioned close together along the Y
axis to provide near equal moments about the Z axis. The weights of
counterweights 1130, 1132 can be slightly different to account for
their varying location along the Y axis so that each counterweight
generates the same moment about the center of gravity of the
engine.
Counterweights 1130, 1132, in addition to providing the desired
moments about the Z axis, create undesirable lateral forces
directed perpendicular to the Y-axis (in the direction of the X
axis), which act on the U-joint or other mount supporting
transition arm 310. When counterweights 1130, 1132 are positioned
as shown in FIG. 41, this does not occur because the upward force,
F.sub.u, and the downward force, F.sub.d, cancel. But, when
counterweights 1130, 1132 are positioned other than as shown in
FIG. 41 or 180.degree. from that position, this force is applied to
the mount. For example, as shown in FIG. 42, forces F.sub.x3 and
F.sub.x4 create a side force, F.sub.5, along the X axis. One
technique of incorporating counterbalances which provide the
desired moments about the Z axis without creating the undesirable
forces on the mount is shown in FIG. 43.
Referring to FIG. 43, a second pair of counterweights 1150, 1152
are provided. Counterweights 1130 and 1152 are mounted to shaft 408
to rotate clockwise with shaft 408. Counterweights 1132 and 1150
are mounted to a cylinder 1154 surrounding shaft 408 which is
driven through pulley system 1134 to rotate counterclockwise.
Counterweights 1130, 1152 extend from opposite sides of shaft 408
(counterweight 1130 being directed downward in FIG. 43, and
counterweight 1152 being directed upward), and counterweights 1132,
1150 extend from opposite sides of cylinder 1154 (counterweight
1132 being directed upward, and counterweight 1150 being directed
downward). Counterweights 1130, 1150 are aligned on the same side
of shaft 408, and counterweights 1132, 1152 are aligned on the
opposite side of shaft 408.
Referring to FIG. 44, with counterweights 1130, 1132, 1150, 1152
positioned as shown, the centrifugal forces due to the rotation of
counterweights 1130, 1132 creates forces, F.sub.x3 and F.sub.x4,
respectively, in the same direction in the X axis, and the
centrifugal forces due to the rotation of counterweights 1150, 1152
creates forces, F.sub.x5 and F.sub.x6, respectively, in the
opposite direction in the X axis. Since F.sub.x3 and F.sub.x4 are
equal and opposite to F.sub.x5 and F.sub.x6, these forces cancel
such that no undesirable lateral forces are applied to the
transition arm mount.
In addition, as discussed above, movement of pistons 306, 308 in
the direction of the Y axis, in the plane of the XY axes, creates a
moment about the Z axis, M.sub.zy. Since counterweights 1130, 1132,
1150, 1152 are substantially the same weight, and counterweights
1150, 1152 are located further from the Z axis than counterweights
1130, 1132, the moment created by counterweights 1150, 1152 is
larger than the moment created by counterweights 1130, 1132 such
that these forces act together to create a moment about the Z axis,
M.sub.zx, which acts in the opposite direction to M.sub.zy. The
weight of counterweights 1130, 1132, 1150, 1152 is selected such
that M.sub.zx substantially cancels M.sub.zy.
When pistons 306, 308 are centered on the X axis (FIG. 43), there
is no moment about the Z axis. In this position, counterweights
1130, 1132 are oppositely directed and counterweights 1150, 1152
are oppositely directed such that the moments created about the X
axis by the centrifugal forces on the counterweights cancel.
Likewise, the forces created perpendicular to the Y axis, F.sub.u
and F.sub.d, cancel. The same is true after 180 degrees of rotation
of shafts 408 and 608, when the pistons are again centered on the X
axis.
Counterweight 1130 can be incorporated into flywheel 1108, thus
eliminating one of the counterweights.
Referring to FIG. 45, another configuration for balancing a piston
engine having two double ended pistons 306, 308 180.degree. apart
around the Y axis includes two members 1160, 1162, which each
simulate a double ended piston, and two counterweights 1164, 1166.
Members 1160, 1162 are 180.degree. apart and equally spaced between
pistons 306, 308. Counterweights 1164, 1166 extend from opposite
sides of shaft 408, with counterweight 1166 being spaced further
from the Z axis than counterweight 1164. Here again, counterweight
1114a mounted to rotating member 1108 is sized to only balance
transition arm 310.
Movement of members 1160, 1162 along the Y axis, in the plane of
the YZ axis, creates a moment about the X axis, M.sub.xy. When
counterweights 1164, 1166 are positioned as shown in FIG. 45, the
centrifugal forces due to the rotation of counterweights 1164, 1166
creates forces, F.sub.u and F.sub.d, respectively, in opposite
directions along the Z axis. Since counterweight 1166 is located
further from the Z axis than counterweight 1164, the moment created
by counterweight 1166 is larger than the moment created by
counterweight 1164 such that these forces act together to create a
moment about the X axis, M.sub.xz, which acts in the opposite
direction to M.sub.xy. The weight of counterweights 1164, 1166 is
selected such that M.sub.xz substantially cancels M.sub.xy.
In addition, since the forces, F.sub.u and F.sub.d, are oppositely
directed, these forces cancel such that no undesirable lateral
forces are applied to the transition arm mount.
Referring to FIG. 46, movement of pistons 306, 308 along the Y
axis, in the plane of the XY axes, creates a moment about the Z
axis, M.sub.zy. When counterweights 1164, 1166 are positioned as
shown in FIG. 45, the centrifugal forces due to the rotation of
counterweights 1164, 1166 creates forces, F.sub.x7 and F.sub.x8,
respectively, in opposite directions along the X axis. These forces
act together to create a moment about the Z axis, M.sub.zx, which
acts in the opposite direction to M.sub.zy. The weight of
counterweights 1164, 1166 is selected such that M.sub.zx
substantially cancels M.sub.zy.
In addition, since the forces perpendicular to Y axis, F.sub.x7 and
F.sub.x8, are oppositely directed, these forces cancel such that no
undesirable lateral forces are applied to the transition arm
mount.
Counterweight 1164 can be incorporated into flywheel 1108 thus
eliminating one of the counterweights.
The piston engine can include any number of pistons and simulated
piston counterweights to provide the desired balancing, e.g., a
three piston engine can be formed by replacing one of the simulated
piston counterweights in FIG. 43 with a piston, and a two piston
engine can be formed with two pistons and one simulated piston
counterweight equally spaced about the transition arm.
If the compression ratio of the pistons is changed, the position of
the counterweights along shaft 408 is adjusted to compensate for
the resulting change in moments.
Another undesirable force that can be advantageously reduced or
eliminated is a thrust load applied by transition arm 310 to
flywheel 1108 that is generated by the circular travel of
transition arm 310. Referring to FIG. 47, the circular travel of
transition arm 310 generates a centrifugal force, C.sub.1, which is
transmitted through nose pin 320 and sleeve bearing 376 to flywheel
1108. Although counterweight 1114 produces a centrifugal force in
the direction of arrow 2010 which balances force C.sub.1, at the
15.degree. angle of nose pin 320, a lateral thrust, T, of 26% of
the centrifugal force, C.sub.1, is also produced. The thrust can be
controlled by placing thrust bearings or tapered roller bearings
2040 on shaft 408.
To reduce the load on bearings 2040, and thus increase the life of
the bearings, as shown in FIG. 48, nose pin 320a is spherically
shaped with flywheel 1108a defining a spherical opening 2012 for
receiving the spherical nose pin 320a. Because of the spherical
shapes, no lateral thrust is produced by the centrifugal force,
C.sub.1.
FIG. 49 shows another method of preventing the application of a
thrust load to the transition arm. Here, a counterbalance element
2014, rather than being an integral component of the flywheel
1108b, is attached to the flywheel by bolts 2016. The nose pin 320b
includes a spherical portion 2018 and a cylindrical portion 2020.
Counterbalance element 2014 defines a spherical opening 2022 for
receiving spherical portion 2018 of nose pin 320b. Cylindrical
portion 2020 of nose pin 320b is received within a sleeve bearing
2024 in a cylindrical opening 2026 defined by flywheel 1108b.
Because of the spherical shapes, no lateral thrust is produced by
the centrifugal force, C.sub.1.
Counterbalance element 2014 is not rigidly held to flywheel 1108b
so that there is no restraint to the full force of the
counterweight being applied to the spherical joint to cancel the
centrifugal force created by the circular travel of transition arm
310. For example, a clearance space 2030 is provided in the screw
holes 2032 defined in counterbalance element 2014 for receiving
bolts 2016.
One advantage of this embodiment over that of FIG. 48 is that the
life expectancy of a cylindrical joint with a sleeve bearing
coupling the transition arm to the flywheel is longer than that of
the spherical joint of FIG. 48 coupling the transition arm to the
flywheel.
Referring to FIG. 50, a hydraulic pump 2110 includes a stationary
housing 2112 defining a chamber 2114, and a rotating drum or
cylinder 2116 located within chamber 2114. Cylinder 2116 includes
first and second halves 2116a, 2116b defining a plurality of piston
cavities 2117. Each cavity 2117 is formed by a pair of aligned
channels 2118, 2120 joined by an enlarged region 2122 defined
between cylinder halves 2116a, 2116b. Located within each cavity
2117 is a double ended piston 2124, here six pistons being shown,
though fewer or more pistons can be employed depending upon the
application. Each double ended piston is mounted to a transition
arm 2126 by a joint 2128, as described above. Transition arm 2126
is supported on a universal joint 2130 mounted to cylinder 2116
such that pistons 2124 and transition arm 2126 rotate with cylinder
2116.
The angle, .gamma., of transition arm 2126 relative to longitudinal
axis, A, of pump 2110 is adjustable to reduce or increase the
output from pump 2110. Pump 2110 includes an adjustment mechanism
2140 for adjusting and setting angle, .gamma.. Adjustment mechanism
2140 includes an arm 2142 mounted to a stationary support 2144 to
pivot about a point 2146. An end 2148 of arm 2142 is coupled to a
first end 2152 of a control rod 2150 by a pin 2154. Arm 2142
defines an elongated hole 2155 which receives pin 2154 and allows
for radial movement of arm 2142 relative to control rod 2150 when
arm 2142 is rotated about pivot point 2146. A second end 2156 of
rod 2150 has laterally facing gear teeth 2158. Gear teeth 2158 mate
with gear teeth 2160 on a link 2162 mounted to pivot about a point
2164. An end 2166 of link 2162 is coupled to transition arm 2126 at
a pivot joint 2168. Transition arm nose pin 2126a is supported by a
cylindrical pivot pin 370 (not shown) and sleeve bearing 376 (not
shown), as described above with reference to FIGS. 25-25b, such
that transition arm 2126 is free to rotate relative to adjustment
mechanism 2140.
Angle, .gamma., is adjusted as follows. Arm 2142 is rotated about
pivot point 2146 (arrow, B). This results in linear movement of rod
2150 (arrow, C). Because of the mating of gear teeth 2158 and 2160,
the linear movement of rod 2150 causes link 2162 to rotate about
pivot point 2164 (arrow, D), thus changing angle, .gamma.. After
the desired angle has been obtained, the angle is set by fixing arm
2142 using an actuator (not shown) connected to end 2142a of arm
2142.
Due to the fixed angle of transition arm 2126 (after adjustment to
the desired angle), and the coupling of transition arm 2126 to
pistons 2124, as the transition arm rotates, pistons 2124
reciprocate within cavities 2117. One rotation of cylinder 2116
causes each piston 2124 to complete one pump and one intake
stroke.
Referring also to FIG. 51, pump 2110 includes a face valve 2170
which controls the flow of fluid, e.g., pressurized hydraulic oil,
in pump 2110. On the intake strokes, fluid is delivered to channels
2118 and 2120 through an inlet 2172 in face valve 2170. Inlet 2172
is in fluid communication with an inlet port 2174. Inlet port 2174
includes a first section 2174a that delivers fluid to channels
2120, and a second section 2174b that delivers fluid to channels
2118. First section 2174a is located radially outward of second
section 2174b. On the pump strokes, fluid is expelled from channels
is 2118 and 2120 through an outlet 2176 in face valve 2170. Outlet
2176 is in fluid communication with an outlet port 2178. Outlet
port 2178 includes a first section 2178a via which fluid expelled
from channels 2120 is delivered to outlet 2176, and a second
section 2178b via which fluid expelled from channels 2118 is
delivered to outlet 2176. First section 2178a is located radially
outward of second section 2178b.
Referring also to FIG. 52, cylinder 2116 defines six flow channels
2180 through which fluid travels to and from channels 2120. Flow
channels 2180 are radially aligned with port sections 2174a and
2178b; and channels 2118 are radially aligned with port sections
2174b and 2178b. When a first end 2124a of piston 2124 is on the
intake stroke and a second end 2124b of piston 2124 is on the pump
stroke, cylinder 2116 is rotationally aligned relative to
stationary face valve 2170 such that the respective channel 2118 at
first end 2124a of piston 2124 is aligned with inlet port section
2174b, and the respective flow channel 2180 leading to a respective
channel 2120 at second end 2124b of piston 2124 is aligned with
outlet port section 2178a.
Cylinder 2116 further defines six holes 2182 for receiving
connecting bolts (not shown) that hold the two halves 2116a, 2116b
of cylinder 2116 together. Cylinder 2116 is biased toward face
valve 2170 to maintain a valve seal by spring loading. Referring to
FIG. 53, a face plate 2190 defining outer slots 2192a and inner
slots 2192b is positioned between stationary face valve 2170 and
rotating cylinder 2116 to act as a bearing surface. Outer slots
2192a are radially aligned with port sections 2174a and 2178a, and
inner slots 2192b are radially aligned with port sections 2174b and
2178b.
Referring to FIG. 54, a pump or compressor assembly 2210 for
varying the stroke of pistons 2212, e.g., a pump with single ended
pistons having a piston 2212a at one end and a guide rod 2212b at
the opposite end, has the ability to vary the stroke of pistons
2212 down to zero stroke and the capability of handling torque
loads as high as a fixed stroke mechanism. Assembly 2210 is shown
with three pistons, though two or more pistons can be employed.
Assembly 2210 includes a transition arm 2214 coupled to pistons
2212 by any of the methods described above. Transition arm 2214
includes a nose pin 2216 coupled to a rotatable flywheel 2218. The
rotation of flywheel 2218 and the linear movement of pistons 2212
are coupled by transition arm 2214 as described above.
The stroke of pistons 2212, and thus the output volume of assembly
2210, is adjusted by changing the angle, .delta., of nose pin 2216
relative to assembly axis, A. Angle, .delta., is changed by
rotating transition arm 2214, arrow, E, about axis, F, of support
2220, e.g., a universal joint. Flywheel 2218 defines an arced
channel 2220 housing a bearing block 2222. Bearing block 2222 is
slidable within channel 2220 to change the angle, .delta., while
the cantilever length, L, remains constant and preferably as short
as possible for carrying high loads. Within bearing block 2222 is
mounted a bearing 2224, e.g., a sleeve or rolling bearing, which
receives nose pin 2216. Bearing block 2222 has a gear toothed
surface 2226, for reasons described below.
Referring also to FIG. 55, to slide bearing block 2222 within
channel 2220, a control rod 2230, which passes through and is
guided by a guide bushing 2231 within cylindrical opening 2232 in
main drive shaft 2234 and rotates with drive shaft 2234, includes a
toothed surface 2236 which engages a pinion gear 2238. Pinion gear
2238 is coupled to gear toothed surface 2226 of bearing block 2222,
and is mounted in bushings 2240. Axial movement of control rod
2230, in the direction of arrow, B, causes pinion gear 2238 to
rotate, arrow, C. Rotation of pinion gear 2238 causes bearing block
2222 to slide in channel 2220, arrow D, circumferentially about a
circle centered on U-joint axis, F, thus changing angle, .delta..
The stroke of pistons 2212 is thus adjusted while flywheel 2218
remains axially stationary (along the direction of arrow, B).
Other embodiments are within the scope of the following claims.
For example, the double-ended pistons of the forgoing embodiments
can be replaced with single-ended pistons having a piston at one
end of the cylinder and a guide rod at the opposite end of the
cylinder, such as the single-ended pistons shown in FIG. 32 where
element 604, rather than being a pump piston acts as a guide
rod.
The various counterbalance techniques, variable-compression
embodiments, and piston to transition arm couplings can be
integrated in a single engine, pump, or compressor.
* * * * *
References